To hit:

Odds of successful hit based on difference between defense bonus and attack bonus

-10

Only succeed on a 20 (see critical hit section)

-9

10%

-8

15%

-7

20%

-6

25%

-5

30%

-4

35%

-3

40%

-2

45%

-1

50%

+0

55%

+1

60%

+2

65%

+3

70%

+4

75%

+5

80%

+6

85%

+7

90%

+8

95%

+9

only fail on 1

Status effects:

bruised

Odds to get a bruise based on difference between toughness bonus and damage bonus

-13

5%

-12

10%

-11

15%

-10

20%

-9

25%

-8

30%

-7

35%

-6

40%

-5

45%

-4

50%

-3

55%

-2

60%

-1

65%

+0

70%

+1

75%

+2

80%

+3

85%

+4

90%

+5

95%

stunned

Odds to get stunned based on the difference between toughness bonus and damage bonus

-8

5%

-7

10%

-6

15%

-5

20%

-4

25%

-3

30%

-2

35%

-1

40%

+0

45%

+1

50%

+2

55%

+3

60%

+4

65%

+5

70%

+6

75%

+7

80%

+8

85%

+9

90%

+10

95%

staggered

Odds to get staggered based on the difference between toughness bonus and damage bonus

-3

5%

-2

10%

-1

15%

+0

20%

+1

25%

+2

30%

+3

35%

+4

40%

+5

45%

+6

50%

+7

55%

+8

60%

+9

65%

+10

70%

+11

75%

+12

80%

+13

85%

+14

90%

+15

95%

unconscious

Odds to become unconscious based on the difference between toughness bonus and damage bonus

+1

5%

+2

10%

+3

15%

+4

20%

+5

25%

+6

30%

+7

35%

+8

40%

+9

45%

+10

50%

+11

55%

+12

60%

+13

65%

+14

70%

+15

75%

+16

80%

+17

85%

+18

90%

+19

95%

what these tables do

What does this mean? With this data you can gain the odds of any standard attack dealing one of the general effects of damage.

To do this you find the odds of the to hit and then the most severe status effect you want to see the odds for inflicting. Due to how M&M works you get all the other status effects on this success so it is pointless to find them all individually if you are looking out for the most severe one.

After this you multiply your To hit odds by the status odds you are looking for.

For example We will say we have a character that is -2 on the to hit chart and +2 on the status charts, we will look for stagger as the most severe effect. This gives us 45% to hit and 30% for the stagger.

So 45%(.45)* 30%(.30) gives us a 13%(.135) chance to cause the staggered condition on the target.

Critical hits:

Critical hits mess with this system due to how they work. For the To hit roll nothing changes as the crit has to be confirmed but for the status effects the damage bonus gets +5. What this means is if you want a true calculation of your statistics for causing the stat you should include the critical odds too.

Using our previous example we have a 13% chance to cause staggered now for the crit odds we now have 55%(.55) of causing the staggered condition. Now let us add the fact that we have improved critical on this attack, which increases our chance to cause the critical by 5% each time it is applied.

so our odds of this critical effect coming into play is 10% (5% for natural crit + 5%*ranks of improved critical)

The new stager chance is 45%(.45)*55%(.55) giving us a 24%(.2475) to cause stagger 10% of the time in this scenario.

For further accuracy we can say the odds for a critical stager is the chance to get the critical multiplied by the final result of a critical stager.

So in this case it is 10%(.10)* 24%(.2475) giving us 2%(.02475) of scoring a critical stager under these conditions.

What this means:

For DMs that keep track of their players sheets this means they can tune in how dangerous the foes they put into play namely by figuring out how easy these foes can cause staggered condition or even the unconscious condition.

A DM should also realize that what they will get will generally be the lowest odds of the event happening as bruise/injury constantly reduces your player characters toughness bonus; Also catching them off guard, stunning, or otherwise decreasing their dodge/defense bonus will overall increase the odds of the event too. You could account for denied dodge bonus and maybe some effects but it's best if you just take the general no bruised/injury and no surprise round and have that as the best the players will have.

For players not so much as you would need to know the foes you are facing, though if you wish to figure out how you stack up against any given PL or to see if your tradeoffs are really worth it you could do it if you take standard foes with defense bonus and toughness bonus at the cap for their respective power level.

Final facts.

instagib

The odds of instant death between two equally matched opponents (+0 in both to hit and status effects) is 55%(.55)*20%(.20)* the chance of a critical so for no improved critical 5%(.5).

So for no improved critical you will see fights ended about .5%(.0055)or 1 in ~181 for equal characters to end combat on the first successful hit.

Average status effect table

For the sake of argument all tables are used at the +0 setting without critical.

Chance of bruise 38%(.385)

Chance of Stun 24%(.2475)

Chance of staggered 11%(.11)

Chance of Unconscious is 0% as it is impossible for a failure of 15 with a difference of 0. But after an bruise/injury is given the chance is 2%(.0275).

Trade offs

To give a basic example I will use bruised for demonstration and the other character will be PL appropriate.

Defense for Toughness trade off/DC for Attack

39%(.39) chance for a bruise.

For 1 points trade off

39%(.39) chance for a bruise.

For 2 points trade off

38%(.385) chance for a bruise.

For 3 points trade off

37%(.375) chance for a bruise.

For 4 points trade off

36%(.36) chance for a bruise.

For 5 points trade off

34%(.34) chance for a bruise.

For 6 points trade off

31%(.315) chance for a bruise.

For 7 points trade off

28%(.285) chance for a bruise.

For 8 points trade off

25%(.2375) chance for a bruise.

For 9 points trade off (attack will hit as long as attack roll was not a natural 1)

19%(.19) chance for a bruise.

For 10 points trade off(attack will hit as long as attack roll was not a natural 1)

Toughness for Defense trade off/Attack for DC

37%(.375) chance for a bruise.

For 1 point trade off

36%(.36) chance for a bruise.

For 2 points trade off

34%(.34) chance for a bruise.

For 3 points trade off

31%(.315) chance for a bruise.

For 4 points trade off

28%(.285) chance for a bruise.

For 5 points trade off

25%(.25) chance for a bruise.

For 6 points trade off (on a successful a hit their will be a bruise/injury)

20%(.20) chance for a bruise.

For 7 points trade off (on a successful a hit their will be a bruise/injury)

15%(.15) chance for a bruise.

For 8 points trade off (on a successful a hit their will be a bruise/injury)

10%(.10) chance for a bruise.

For 9 points trade off (on a successful a hit their will be a bruise/injury)

5%(.5) chance for a bruise.

For 10 points trade off(on a successful a hit their will be a bruise/injury)

Conclusion, in straight up damage avoiding abilities trading toughness for defense is Superior to Defense for toughness. Though at the extreme ends you will be taking major risks where any attack could potentially knock you out if you are hit.

Trading Defense for Toughness causes your character to become harder to knock unconscious in more ways the one. Due to how bruises/injuries work your toughness is always going down, and thus your chance for being knocked unconscious up. With additional toughness you effectively gain a buffer zone to PL appropriate attacks in that it will take an additional injury per point of trade off to even have a chance of causing the unconscious effect. When trading Defense for Toughness you should take 2 points of trade off as it is statistically the same and offers more benefit that comes with above PL toughness, though at the extreme end you will always get hit but will generally take a while for you to be knocked unconscious with PL appropriate attacks.

Toughness for Defense trade off has additional benefits for traditional damaging abilities as your other saves are unaffected. As long as it requires a general attack roll and does not require a toughness save You have superior odds to avoid it then the general charter with equal amounts of the save. The very down side is that every point you take gives a chance for unconscious happening on any PL appropriate attack and after trading off for 5 points your toughness through will only be useful for figuring out how much you fail by. In the long run this may be the better option but everything that doesn't require a toughness save will more then likely happen.

For the Attack/DC trade offs it seems that DC for Attack is the only one worthwhile for the first or second points and after that it just lowers your chance to cause a bruise, and has lowered chance for unconscious status effect and may not even get it without one or two extra attacks for it. The only benefits you could get from Attack for DC is the chance for causing the unconscious effect more readily if you could hit them.